长江口2016年冬季浮游植物类群及其与环境因子的关系

Feature of phytoplankton groups in Yangtze Estuary and its relationship with environmental factors in winter,2016

2016年12月对长江口冬季浮游植物分布进行详细调查,并采用典型对应分析方法研究了其与环境因子之间的关系。小潮期间和大潮调查获取的浮游植物分别为96种和63种(含变种和变型),硅藻、蓝藻和绿藻是主要的浮游植物类群,主要的优势种为微囊藻(Microcystis spp)和中肋骨条藻(Skeletonema costatum)。调查获取的浮游植物可以分为4个生态类群:淡水类群、河口半咸水类群、近岸低盐性类群、海洋广布性类群。Margalef物种丰富度指数、Shannon-Wiener物种多样性指数、Pielou均匀度指数分布显示,调查区东北部浮游植物多样性程度较高,物种均一性相对较高。物种与环境的典型对应分析显示:长江径流与海水共同决定的盐度、电导率、浊度,以及PO4-P、SiO3-Si营养盐是决定长江口浮游植物分布的关键环境因子。

An integrated survey of the Yangtze Estuary was conducted in December 2016 to obtain the information of the phytoplankton groups and directed gradient analysis were carried out to explore the relationship between phytoplankton distribution and the environmental factors.96 and 63 phytoplankton species were identified during the neap tide period and spring tide period.Diatom,blue algae and green algae were the major phytoplankton group in survey area.Microcystis spp and Skeletonema costatum were the dominant species in the studied area.Based on the ecological characteristics and the distribution,the phytoplankton can be divided into four ecological groups:groups of freshwater,estuarine brackish water groups,nearshore low salt groups,ocean s groups.Margalef,Shannon-Wiener and Pielou’s index were unevenly distributed in the study areas with high species diversity and evenness in Northeast areas.Canonical correspondence analysis(CCA)results of the relationship between phytoplankton species and environmental factors indicated that the salinity,conductivity,turbidity and nutrient salts jointly determined by the runoff of the Yangtze River and seawater determine the distribution of the phytoplankton in the Yangtze Estuary.